Deep-sea benthic crustacean and annelid data from the Bering Sea

Samples of Crustacea and Annelida (Polychaeta, Sipuncula, and Hirudinea) were collected in the Bering Sea and the northwestern Pacific Ocean during scientific cruise SO-249 BERING in 2016. Biological samples were collected from 32 locations by the team on-board RV Sonne using a chain bag dredge at depths ranging between 330–5,070 m, and preserved in 96% ethanol. Specimens were morphologically identified to the lowest taxonomic level possible using a Leica M60 stereomicroscope. The generated data here comprise taxonomic information as well as annotated bathymetric and biogeographic information from a total of 78 samples (26 Crustacea, 47 Polychaeta, 4 Sipuncula, and 1 Hirudinea). The dataset was prepared following Darwin Core Biodiversity standards for FAIR data sharing based on Ocean Biodiversity Information System (OBIS) and Global Biodiversity Facility (GBIF) guidelines. The standardised digitised data were then mobilised to both OBIS and GBIF under CC BY 4.0 licence to publicly share and adopt the data. As records of these important marine taxa from bathyal and abyssal depths are sparse, especially from the deep Bering Sea, the herein generated and digitised data aid in filling existing knowledge gaps on their diversity and distribution in that region. As part of the “Biogeography of the NW Pacific deep-sea fauna and their possible future invasions into the Arctic Ocean” (BENEFICIAL) project, this dataset thus not only increases our knowledge in re-assessing and uncovering the deep-sea diversity of these taxa, but also serves policy and management sectors by providing first-hand data for global report assessments.


a b s t r a c t
Samples of Crustacea and Annelida (Polychaeta, Sipuncula, and Hirudinea) were collected in the Bering Sea and the northwestern Pacific Ocean during scientific cruise SO-249 BERING in 2016. Biological samples were collected from 32 locations by the team on-board RV Sonne using a chain bag dredge at depths ranging between 330-5,070 m, and preserved in 96% ethanol. Specimens were morphologically identified to the lowest taxonomic level possible using a Leica M60 stereomicroscope. The generated data here comprise taxonomic information as well as annotated bathymetric and biogeographic information from a total of 78 samples (26 Crustacea, 47 Polychaeta, 4 Sipuncula, and 1 Hirudinea). The dataset was prepared following Darwin Core Biodiversity standards for FAIR data sharing based on Ocean Biodiversity Information System (OBIS) and Global Biodiversity Facility (GBIF) guidelines. The standardised digitised data were then mobilised to both OBIS and GBIF under CC BY 4.0 licence to publicly share and adopt the data. As records of these important marine taxa from bathyal and abyssal depths are sparse, especially from the deep Bering Sea, the herein generated and digitised data aid in filling existing knowledge gaps on their diversity and distribution in that region. As part of the "Biogeography of the NW Pacific deep-sea fauna and their possible future invasions into the Arctic Ocean" (BENEFICIAL) project, this dataset thus not only increases our knowledge in re-assessing and uncovering the deep-sea diversity of these taxa, but also serves policy and management sectors by providing first-hand data for global report assessments. ©

Value of the Data
• The absence of these raw records of deep-sea crustacean and annelid occurrences from the Bering Sea and the northwestern Pacific Ocean, particularly at bathyal and abyssal depths, constitutes a knowledge gap. Thus, the digitization of the present information adds valuable occurrence and diversity data for these taxa, allowing researchers to reassess their species richness patterns in that region.
• The data generated here further provide information needed to predict potential distribution range shifts of these taxa as a result of future climate change and growing anthropogenic stresses. • In addition to providing information for data scientists and ecologists looking to analyse large-scale biodiversity and distribution patterns, the occurrence records included in this dataset aid taxonomists in understanding the patterns of distribution of the taxa herein described. • In order to protect the deep sea as a vulnerable ecosystem from anthropogenic activities like deep-sea mining and climate change-induced alterations, this data can be used in policy-making processes, including providing data for deep-sea biodiversity assessment reports and stewardships.

Objective
As contribution to and part of the "Biogeography of the NW Pacific deep-sea fauna and their possible future invasions into the Arctic Ocean"-Project (BENEFICIAL; [ 6 , 7 ]), these data aid in (i) uncovering the distribution and diversity patterns of these taxa in the northwestern Pacific and (ii) potential shifts of key species into the Arctic Ocean due to the anthropogenic climate change and a potential invasion of alien species from the lower to the higher latitudes.
The crustacean records of the herein described dataset add valuable biodiversity data of otherwise poorly studied marine regions of the northwest Pacific Ocean, that has been studied in regard to crustacean biodiversity patterns in Knauber et al. [5] , thus complementing the analyses to cover the whole geographic extent of the northwest Pacific Ocean.

Data Description
The herein presented dataset comprises new, unpublished specimen records of Crustacea, Polychaeta, Sipuncula, and Hirudinea from the Bering Sea and the northwestern Pacific Ocean ( Fig. 1 ), collected during scientific cruise SO-249 BERING. All data were formatted based on the Darwin Core standard [1] , quality control of the generated data was performed to allow for FAIR data sharing. In total, the dataset comprises 78 unique occurrence records, of which 26 belong to Crustacea, one belongs to Hirudinea, 47 belong to Polychaeta and four belong to Sipuncula. All polychaete records were identified to family level, while only 46.2 % of the crustacean records could be identified to family level or lower ranks (genus, species). The complete occurrence record dataset is available in OBIS [8] and GBIF [9] . These macrobenthic species records are complemented by bathymetric and biogeographic metadata as extracted from their corresponding station data ( Table 1 ). In OBIS the stored data is available in two separate CSV-files, one containing the occurrence data, the other one containing sampling measurement information. The GBIF database offers three different data download CSV-formats: (1) Simple comprises the interpreted data and coordinates; (2) Darwin Core Archive contains raw, interpreted, multimedia and coordinate data; and (3) Species comprises the interpreted data.

Experimental Design, Materials and Methods
In 2016, the scientific cruise SO-249 BERING explored the deep-sea of the western Bering Sea, the northwestern Pacific Ocean, as well as the area surrounding the Aleutian Islands and Aleutian Trench using deep-sea RV Sonne [2] .
Rectangular chain bag dredges were used to conduct geological and biological sampling. A total of 150 dredge hauls, of which 112 contained macrofaunal organisms, yielded about 1,500 macrofaunal specimens that were deposited in the collections of the Museum für Naturkunde  in Berlin, Germany [2] . All specimens were preliminarily sorted and selected megafaunal specimens (Cephalopoda: Octopoda) were analysed in-depth [10] . Those samples belonging to either Crustacea, Polychaeta, Sipuncula or Hirudinea were morphologically identified to the lowest taxonomic rank possible based on taxonomic keys and literature [11][12][13] using a Leica M60 stereomicroscope. Subsequently, the specimen record dataset was prepared based on the Darwin Core format [1] for submission to the OBIS [8] and GBIF [9] open-access databases, including detailed biogeographic metadata as extracted from the cruise report [2] .

Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.